Carbonic anhydrase inhibitors. Inhibition of the beta-class enzymes from the fungal pathogens Candida albicans and Cryptococcus neoformans with aliphatic and aromatic carboxylates

Bioorg Med Chem. 2009 Apr 1;17(7):2654-7. doi: 10.1016/j.bmc.2009.02.058. Epub 2009 Mar 5.


The inhibition of the beta-carbonic anhydrases (CAs, EC from the pathogenic fungi Cryptococcus neoformans (Can2) and Candida albicans (Nce103) with carboxylates such as the C1-C5 aliphatic carboxylates, oxalate, malonate, maleate, malate, pyruvate, lactate, citrate and some benzoates has been investigated. The best Can2 inhibitors were acetate and maleate (K(I)s of 7.3-8.7 microM), whereas formate, acetate, valerate, oxalate, maleate, citrate and 2,3,5,6-tetrafluorobenzoate showed less effective inhibition, with K(I)s in the range of 42.8-88.6 microM. Propionate, butyrate, malonate, L-malate, pyruvate, L-lactate and benzoate, were weak Can2 inhibitors, with inhibition constants in the range of 225-1267 microM. Nce103 was more susceptible to inhibition with carboxylates compared to Can2, with the best inhibitors (maleate, benzoate, butyrate and malonate) showing K(I)s in the range of 8.6-26.9 microM. L-Malate and pyruvate together with valerate were the less efficient Nce103 inhibitors (K(I)s of 87.7-94.0 microM), while the remaining carboxylates showed a compact behavior of efficient inhibitors (K(I)s in the range of 35.1-61.6 microM). Notably the inhibition profiles of the two fungal beta-CAs was very different from that of the ubiquitous host enzyme hCA II (belonging to the alpha-CA family), with maleate showing selectivity ratios of 113.6 and 115 for Can2 and Nce103, respectively, over hCA II inhibition. Therefore, maleate is a promising starting lead molecule for the development of better, low nanomolar, selective beta-CA inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetic Acid / chemistry
  • Acetic Acid / pharmacology
  • Benzoates / chemistry
  • Benzoates / pharmacology
  • Butyrates / chemistry
  • Butyrates / pharmacology
  • Candida albicans / enzymology*
  • Carbonic Anhydrase Inhibitors / chemistry
  • Carbonic Anhydrase Inhibitors / pharmacology*
  • Carbonic Anhydrases / chemistry*
  • Carbonic Anhydrases / metabolism
  • Carboxylic Acids / chemistry
  • Carboxylic Acids / pharmacology*
  • Catalytic Domain
  • Cryptococcus neoformans / enzymology*
  • Maleates / chemistry
  • Maleates / pharmacology
  • Malonates / chemistry
  • Malonates / pharmacology
  • Structure-Activity Relationship
  • Zinc / chemistry


  • Benzoates
  • Butyrates
  • Carbonic Anhydrase Inhibitors
  • Carboxylic Acids
  • Maleates
  • Malonates
  • maleic acid
  • malonic acid
  • Carbonic Anhydrases
  • Zinc
  • Acetic Acid